Abstract: Method of assay of enzymatic activity, comprising projecting excitation light to a sample containing an enzyme, a substrate which forms a product by action of the enzyme, and a reference substance which is insensitive to the action of the enzyme but emits fluorescence; obtaining a first measured value of fluorescence intensity of the sample at a first wavelength region which includes fluorescence emitted by the substrate or the product at least, obtaining a second measured value of fluorescence intensity at a second wavelength region which is different from the first wavelength region for the first measured value and includes fluorescence emitted by the reference substance; and assaying the enzymatic activity from the ratio of the first measured value to the second measured value and apparatus for performing the method. The method assures high accuracy and high sensitivity of measurement in enzyme labeled immunoassay and enzyme labeled DNA hybridization.

Abstract: Method of assay of enzymatic activity, comprising projecting excitation light to a sample containing an enzyme, a substrate which forms a product by action of the enzyme, and a reference substance which is insensitive to the action of the enzyme but emits fluorescence; obtaining a first measured value of fluorescence intensity of the sample at a first wavelength region which includes fluorescence emitted by the substrate or the product at least, obtaining a second measured value of fluorescence intensity at a second wavelength region which is different from the first wavelength region for the first measured value and includes fluorescence emitted by the reference substance; and assaying the enzymatic activity from the ratio of the first measured value to the second measured value and apparatus for performing the method. The method assures high accuracy and high sensitivity of measurement in enzyme labeled immunoassay and enzyme labeled DNA hybridization.

Abstract: Method of assay of enzymatic activity, including projecting excitation light to a sample containing an enzyme, a substrate which forms a product by action of the enzyme, and a reference substance which is insensitive to the action of the enzyme but emits fluorescence; obtaining a first measured value of fluorescence intensity of the sample at a first wavelength region which includes fluorescence emitted by the substrate or the product at least, obtaining a second measured value of fluorescence intensity at a second wavelength region which is different from the first wavelength region for the first measured value and includes fluorescence emitted by the reference substance; and assaying the enzymatic activity from the ratio of the first measured value to the second measured value and apparatus for performing the method. The method assures high accuracy and high sensitivity of measurement in enzyme labeled immunoassay and enzyme labeled DNA hybridization.

Abstract: A method of monitoring a discharge of a liquid comprises the steps of: measuring a presence or absence of a liquid discharged at an optional area of a passage for the liquid during discharging the liquid of a vessel through the passage; comparing a measurement result obtained in said measuring step with a reference measurement result which are to be obtained when a discharge of the liquid is reliably carried out; and determining as to whether a discharge operation for the liquid has been reliably performed. And an apparatus for performing the method.

Abstract: A quantitative liquid sampling instrument comprises a main body of a pipet device which includes a pipet tip having an opening at its lower end for sucking and discharging a liquid. The pipet tip being in a shape of a tube shell having a cavity for holding a liquid sucked therein through the opening and being made of a transparent or semi-transparent material. The main body further comprising a device for applying a gas pressure for sucking or discharging the liquid to or from the inside of the cavity of the pipet tip.

Abstract: A liquid drain trap device of negative-pressure relay type, which comprises a vertically-elongated hollow container, a liquid drain pipe connected to the side wall of the container and negative-pressure suction device provided in an upper side of the container so as to maintain the interior of the container under a negative pressure and exert a suction force to drain the liquid through the pipe, the liquid drain pipe being made of fluorine resin material at least at its end section projecting into the interior of the container.